plm-lottery/app/api/routes/bets.py

from fastapi import APIRouter, Depends, Request, Response, status
from pydantic import BaseModel
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.errors import from_api_error, http_error
from app.auth.dependencies import get_current_user
from app.bets.service import BetError, place_bet
from app.db.models import User
from app.db.session import get_session

router = APIRouter(prefix="/bets", tags=["bets"])


class BetResponse(BaseModel):
    round_id: int
    bet_txid: str
    bet_amount_sats: int
    status: str


@router.post("", response_model=BetResponse, status_code=status.HTTP_201_CREATED)
async def create_bet(
    request: Request,
    response: Response,
    user: User = Depends(get_current_user),
    session: AsyncSession = Depends(get_session),
) -> BetResponse:
    listener = request.app.state.electrum_listener
    if listener.client is None:
        raise http_error(
            status.HTTP_503_SERVICE_UNAVAILABLE,
            "network_unavailable",
            "not connected to the network, try again shortly",
        )

    async with request.app.state.user_locks.acquire(user.id):
        try:
            participant = await place_bet(session, listener.client, user, network=listener)
        except BetError as exc:
            # A rejected broadcast isn't the client's fault — it's the network
            # refusing our transaction, so it answers 502 rather than 400 (B-07).
            code = (
                status.HTTP_502_BAD_GATEWAY
                if exc.code == "broadcast_failed"
                else status.HTTP_503_SERVICE_UNAVAILABLE  # B-88: write lock not granted, nothing sent
                if exc.code == "service_busy"
                else status.HTTP_400_BAD_REQUEST
            )
            raise from_api_error(code, exc) from exc

    if participant.status == "building":
        # B-76 (TX-20, BET-23): the outcome of the broadcast is uncertain — the tx may
        # already be on the network — so the bet is accepted for processing, not
        # confirmed as sent, and the reconciler settles it.
        response.status_code = status.HTTP_202_ACCEPTED
    return BetResponse(
        round_id=participant.round_id,
        bet_txid=participant.bet_txid,
        bet_amount_sats=participant.bet_amount_sats,
        status=participant.status,
    )